As a red hot, commie, Marxist type I don't hold much for tophat or bowler or flatcap definition of class or whether you've got a mortgage or a degree. What defines class is your relationship to the means of producting and distributing food, clothing, shelter, Nintendo x-boxes, etc. For those that control the means of production, control the means of life itself. In present society, over most of the world, society is divided (not necessarily cleanly) into those who produce (apply labour) but do not possess means of production and those who posses but do not produce (apply labour). Examples of the former type would be someone who lives off the dole, wages, salaries, self-employed, often small to medium company owners still have to labour. Examples of the latter would be someone who lives off profits (dividends from shares, remuneration of directorships - often so enormous they obviously out of all proportion to any work that has been done, fatcat 'salaries').

The state doesn't go around asking what Marxian class you are, but from the figures for marketable wealth, less dwellings, we can infer that the class system is still very much with us. In fact, the class divide is getting greater:
(From www.statistics.gov.uk)
Marketable wealth less value of dwellings (since people's homes are means of production).

1992
The top 1% owned 29%
The top 2-5% owned 24%
The top 6-10% owned 12%
The top 11-25% owned 17%
The top 26-50% owned 12%
The bottom 50% owned 6%

2002
The top 1% owned 35%
The top 2-5% owned 27%
The top 6-10% owned 13%
The top 11-25% owned 13%
The top 26-50% owned 10%
The bottom 50% owned 2%

In 1992, the top 5% owned more than 50% the bottom 95%, but in 2002 the top 5% own almost twice as much. (Thank you Tony)

So I feel working class, in tune with other redhot commie types in the states, and of course working class culture is a result of the above mentioned divisions. But more important than what class you are is the recognition that division of society into classes, the inherent antagonism between classes is a rubbish way of doing things and we could have a society where 100% of people own 100% of the wealth, and then you wouldn't have to worry about class.